Devices for drying glued pencil blanks



July 22, 169 K. ZUBER 3,456,581

DEVICES FOR DRYING GLUED PENCIL BLANKS Filed Nov. 1. 1966 2 Sheets-Sheet1 July 22, 1969 K. ZUBER 3,

DEVICES FOR DRYING GLUED PENCIL BLANKS Filed Nov. 1, 1966 2 Sheets-Sheet2 United States Patent 3,456,581 DEVICES FOR DRYING GLUED PENCIL BLANKSKarl Zuber, Nuremberg, Germany, assignor to BleistiftmaschinenbauDipL-Ing. Karl Zuber, Nuremberg, Germany, a German company Filed Nov. 1,1966, Ser. No. 591,279 Claims priority, application Germany, Mar. 29,1966, B 86,407 Int. Cl. B30b 15/34, 15/32; F26b 9/04 US. Cl. 100-93 4Claims ABSTRACT OF THE DISCLOSURE A device for drying glued pencilblanks including at least one pair of superimposed pressure plates withone of the plates of each pair being movable towards and away from theother plate of each pair and at least one of they plates adapted to beheated. A support for glued blanks next to the pressure plate isprovided together with a pusher adapted to reciprocate the feed blanksin which the length of the support, the pressure plates and the pusherin a direction perpendicular to the direction of movement of the pusheris a multiple of one external dimension of the glued blank.

This invention relates to a device for drying glued pencil blanks havingat least one pair of pressure plates, which are arranged with theirpressure surfaces opposite one another, are movable relatively to oneanother in the direction of a perpendicular to their pressure surfaces,are stationary when the glued blanks are pressed in and at least one ofwhich is adapted to be heated, and having a support for glued blanksnext to the pair of pressure plates and a pusher which is movable overthe support towards the pressure plate and back again.

A usual glued blank has two identical rectangular wooden pieces of smallthickness, and in whose surface defined by length and breadthlongitudinal grooves are formed. The two wooden pieces placed with thelongitudinal grooves opposite one another enclose in the grooves theleads of the pencils to be manufactured. Between the pieces placedagainst one another there is a layer of glue which is still not dry. Inorder to dry the glue quickly so that the two wooden pieces are stucksufficiently firmly to one another, it is customary to press the blank,i.e. press the wooden pieces against one another and in addition heatthem above room temperature. A known device not belonging to the generictype defined for drying glued pencil blanks, which has a caterpillarpress for pressing the glued blanks, has the disadvantage over thedevice of the type defined that a uniform pressure as required to setthe glue can be achieved only with a very complicated construction andtherefore prohibitive costs. The pressure generators together with thepressure plates and the glued material located therein would have torotate. The electrical energy for the pressure generators would have tobe supplied by means of sliding contacts. This disadvantage cannot beavoided by making the pressure plates, although participating in therotation, roll on pressure rollers during the pressing operation. Apartfrom economic considerations on account of the costs of such aconstruction, this solution is in any case not acceptable because aconstant pressure as required for setting of the glue cannot be obtainedbecause of the rolling of individual pressure plates on rollers. Thereis the additional point that in such a construction, the providing ofthe rotating pressure plates with heat energy would present considerabledifficulties and incur economically prohibitive costs.

In another known device for drying glued pencil blanks, the pressuresurface of the pressure plates corresponds substantially to the basearea of the blanks to be treated. This known device has a rotatableframe similar to a Wheel, on which the pressure generators are arrangedradially. The pistons with their pressure plate act radially from theinside towards the outer pressure plate which is fixed rigidly to thewheel member. Each pressure member presses so many glued blanks placedwith their bases upon one another. The wheel @frame is moved onintermittently. At a certain point each pressure member is renderedpressureless after locking of the wheel, so that new glued blanks to bedried can be introduced and these push the dried blanks out on the otherside.

One disadvantage of this known device consists in that on account of thenecessary arrangement of the pressure generators, one pressure generatorper pencil blank area is required. Thus in order to obtain an outputapprocahing that of the invention described below, approximatelyhydraulic cylinders would have to be arranged radially, which with ausual base flange width of 160 mm. for the requisite cylinders, wouldnecessitate an internal circumference of 75 160=12,000 mm. or 12 m. Thiswould correspond to an internal diameter of approximately 4 m. Such amammoth wheel can scarcely be moved by a stepping mechanism of thenecessary switchings per minute. Thus this device does not offer asolution to the problem either. In addition the pressure energy, forwhich only oil comes into consideration, would have to be supplied tothe radial pressure generators expensively by way of a hollow axle withcorresponding ducts.

To avoid the disadvantages of the known devices mentioned, the object ofthe invention consists in providing a device of the type defined withwhich continuous operation is possible. The device is for this purposecharacterized according to the invention by the feature that the lengthof the support, of the pressure plates and of the pusher in thedirection perpendicular to the direction of movement of the pusher is amultiple of one external dimension of a glued blank.

One feature of the device according to the invention is that thepressure plates of one pair are stationary, apart from their pressingmovements, that is movements in the direction of a perpendicular totheir pressure surfaces. When the glued blanks to be dried are beingheated, the pressure plates are stationary. In order that the devicewith this feature is economical, it is advantageously so designed thatseveral pressure plates are arranged next to one another. During thedrying time of one batch of glued blanks pressed by the pressure plates,the next batch of blanks is brought on the support to a point in frontof the pressure plates so that they lie next to one another in rows andwhen the pressure plates are opened, can be pushed in one go between theplates by means of the pusher. The last mentioned feature isadvantageous because the heating members bear against the bases of theblanks. If the heating members were to bear on the side or end surfacesof the blanks transversely to the direction of feed, then they wouldhave to be removed for insertion of the blanks. If the heating memberswere to bear on the side or end surfaces of the blanks in the directionof feed, then the blanks before being inserted would have to be alignedvery accurately with the heating members and the heating members wouldnecessitate a very large overall length of the device. The advantages ofthe last-mentioned feature may therefore only be fully felt if thefurther feature is provided that the pressure plates are used as heatingmembers, in which case they are preferably heated by resistance heatingmeans.

In a preferred embodiment of the device according to the invention,several pressure plates each movable by means of a hydraulic drive andarranged next to and almost touching one another are provided oppositeone large stationary pressure plate in the form of a table plate inonepiece. The movable pressure plates have a pressure area correspondingto a multiple of the base area of the blanks of 7 times 18.4 cm. andeach press their blanks with a force of approximately 2000 kg. Both thepressure plate designed as a table plate and the movable pressure platesare capable of being heated. Between the pressure plates the gluedblanks are placed in two layers and are therefore heated symmetricallyfrom above and below.

The accompanying drawings show a device according to the invention whichcan be supplemented by means of prefabricated units and which with a lowoverall length has an output of uniformly pressed blanks which can beincreased as desired.

In the drawings:

FIGURE 1 is a front view of the device.

FIGURE 2 is a section along the line II-II of FIG- URE 1.

FIGURE 3 is a section along the line IIIIII of FIG- URE 2.

FIGURE 4 is the fragment A of FIGURE 3.

FIGURE 5 is a top view of a supplemented embodiment of the device, and

FIGURE 6 is a section through a pressure plate.

The device shown has curved frame casings 3 having two verticalstandards 3a, 3b which are joined to the top by a cross-head 3c and atthe bottom by a cross-support 3d. Bottom press supports 4a are mountedat one end on the cross-supports 3d of two oppositely arranged framesupports, approximately in the middle thereof. Two upper press supports4b arranged at a distance from one another substantially opposite thebottom press supports 4a are arranged on the cross-heads 3c of bothframe carriers or supports. The vertical standards 3a, 3b, thecross-head 3c, the cross-support 3d, the bottom press support 4a and theupper press support 4b are in each case double T girders.

On the bottom press supports 4a is located a pressure plate designed asa table-plate 8, which extends in one piece from one frame casing 3 tothe other. The upper press supports 4b arranged at a distance from oneanother are joined on their underside by six supporting plates 5 each ata distance from one another. On each supporting plate 5 is provided ahydraulic drive 6, and piston rod 6a thereof projects downwardly throughthe supporting plate. On the projecting end of each piston rod 6a isarranged a pressure plate 7 movable by means of the hydraulic drive 6.

Six movable pressure plates 7 are arranged next to one another in a rowwith slight play between one another. Their pressure surface amounts toa sixth of base area 1a of a glued blank 1 in each case. Their widthcorresponds to the length of one blank. Both the pressure plate designedas a table plate 8 and the movable pressure plates 7 are capable ofbeing heated by electric resistance heating means like the plate of afurnace.

At the level of the pressure plate designed as a table plate 8 isarranged on one side of the pressure plate on the vertical standards 3aa supporting plate 10 extending between two frame casings 3. A rod-likepusher 12 is arranged parallel with the supporting plate and slightlyhigher than the latter. The pusher 12 is capable of being moved by ahydraulic drive 13 which is arranged on each vertical standard 3a.

A conveyor belt 9 of the belt conveyor lies with its upper stringeron'the supporting plate 10'. At its end located in the conveyingdirection is provided transversely thereto a stop 11. Its opposite endextends beyond the supporting plate 10 and takes glued blanks deliveredby a gluing machine 2 producing the glued blanks 1.

On the side remote from the feed conveyor belt 9 is provided awithdrawal conveyor belt 14. This is guided at its end near the gluingmachine outside the frame casing 3 around a roller 16 mounted in holders15. The feed 4. conveyor belt 9 is in the same way at its end located inthe conveying direction guided about a roller 16.

The gluing machine 2 delivers pairs of glued blanks placed on oneanother to the feed conveyor belt 9 preferably at intervals. The blanks1 supplied are situated substantially obliquely to the feed conveyorbelt 9 and are placed by the latter against the stop 11 or againstblanks 1 already adjoining the stop 11. The feed conveyor belt runningbelow the deposited blanks 1, owing to its friction with the blanks laysthem closely next to one another. The deposited blanks 1 rest with theirbase surface on the support, i.e., the feed conveyor belt, with theirlongitudinal side perpendicular to the direction of movement towards thetable plate 8 and heat them. When the pressed blanks are dry, then themovable pressure plates 7 are withdrawn upwards. Then the pusher 12pushes the blanks located on the feed conveyor belt 9 onto the tableplate 8 and the dried blanks located there onto 1 the withdrawalconveyor belt 14, even if they are stuck to the table plate. During thistime the pusher located on the feed conveyor belt 9 prevents the newblanks delivered by the gluing machine 2 from being guided in front ofthe pressure plates. During the drying time of the newly inserted andpressed blanks, a new batch of undried blanks is collected on theconveyor belt. As the exposed time of the glue is approximately 5 to 8minutes, the stay of the blanks on the conveyor belt during the dryingperiod does not harm them.

The movable pressure plate 7 shown in FIGURE 6 is provided with a bottomdisc 17 having a pressure area 7a, which is connected at its center tothe piston rod 6a and has on the piston rod side an external web 18. Inthe space enclosed by the web 18 there is provided on the bottom disc anelectrically insulating layer 19. On this are located insulatedresistance wires 20 which become heated when current is passedtherethrough. On the wires is located a heat insulating layer 22 whichalso covers the inner surface of the web 18 and the piston rod 6a. Thespace enclosed by the web 18 is covered at the top by a cover 23.

I claim:

1. A device for drying glued pencil blanks having at least one pair ofpressure plates, which are arranged with their pressure surfacesopposite one another, are movable relatively to one another in thedirection of a perpendicular to their pressure surfaces, are stationarywhen the glued blanks are pressed in and at least one of which isadapted to be heated, and having a support for glued blanks next to thepair of pressure plates and a pusher which is movable over the supporttowards the pressure plate and back again, characterized by the featurethat the length of the support, of the pressure plates and of the pusherin a direction perpendicular to the direction of movement of the pusheris a multiple of one external dimension of a glued blank.

2. The device as claimed in claim 1, characterized by the feature thatthe upper stringer of a conveyor belt is provided next to the pair ofpressure plates.

3. The device as claimed in claim 2, characterized by the feature thatthe upper stringer is provided as said support and a stop is provided atthe end of the pressure plates located in the conveying directiontransversely to the conveying surface of the upper stringer.

4. The device as claimed in claim 1, characterized by the feature thatseveral movable pressure plates arranged next to one another areprovided opposite one large piece.

stationary pressure plate designed as a table plate in One 2,943,3537/1960 Fraula et a1. 100215 XR 3,079,607 3/ 1963 Iureit.

References Cited 3,288,057 11/1966 Loewenfeld 100218 XR UNITED STATESPATENTS PETER FELDMAN, Primary Examiner Purcell 198-31 5 Mollenhauer10093 XR US. Cl. X.R.

Skoog- Ashford 214 16.4 34-144, 100218, 144-28, 281, 19831, 21416.4

